The present invention relates to a novel photosensitive resin composition or, more particularly, to a photosensitive resin composition capable of giving a layer of the cured resin composition on a substrate surface suitable as a resist in sandblast engraving works by virtue of the good pliability to withstand the mechanical attack in the sandblasting and insusceptibility to accumulation of static electricity which may cause some troubles due to discharge. The invention also relates to a photosensitive dry film for a sandblast resist by the use of the above mentioned novel photosensitive resin composition as well as a method for patterning of a substrate surface by sandblast engraving using the same.
It is sometimes desired to form a relief pattern on the surface of a substrate of a material such as plates of glass, marble, plastic resin and the like for a decorative purpose or for the purpose of patterning in the manufacture of electronic devices such as circuit boards and plasma display panels in which patterns of both a metal and a ceramic are formed on the same substrate surface. One of the methods for such relief patterning is the method of pattern-wise engraving by sandblast in which a layer of a photosensitive resin composition is formed on the substrate surface from which a patterned resist layer is formed by the method of photolithography and the exposed or unmasked areas of the substrate surface are engraved by sandblast with blowing of abrasive particles at the surface.
Various photosensitive resin compositions have been proposed heretofore to serve as a sandblast resist including those comprising an unsaturated polyester resin, unsaturated monomer and photopolymerization initiator disclosed in Japanese Patent Kokai 55-103554 and those comprising a polyvinyl alcohol and diazo resin disclosed in Japanese Patent Kokai 2-69754.
These photosensitive resin compositions, however, have a problem in general that, when a patterned resist layer is formed from the resin composition on the substrate surface and engraving of the substrate surface is performed by sandblast with the resist layer as a masking, the substrate surface is charged with static electricity eventually to cause discharge so that the substrate made from glass or marble is stained or damaged by the occurrence of chipping or a circuit board as the substrate is subject to troubles such as line break and short-circuit due to damages on the wiring pattern or destruction of the insulating layer.